Self-priming pump



Oct. 3, 1939 R. e. BARZEN SELF-PRIMING PUIP Filed Dec. 15, 1936 I N V EN TOR. Richard G Barzen,

ATTORNEY.

Patented Oct. 3, 1939 UNITED STATES PATENT OFFICE SELF-PRIMING PUMP Richard G. Barzen, Kansas City, Mo. Application December 15, 1936, Serial No. 115,921

1 Claim.

The present invention relates to self-priming pump constructions, aiming to provide a novel and improved self-priming feature in apparatus of this character.

One of the objects of the invention is to provide a construction which is of a simple and automatically adjustable character for cooperation with the pumping means in effecting the priming function.

One method of accomplishing this object'is to provide a device operating on the injector principle and in cooperation with the pumping means for displacing either gas or liquid from the suction intake or chamber and. discharging such gas or liquid into' the outlet or discharge line of the pump.

It is also an object of the invention to provide a construction of the character mentioned in which provision is also made for permitting recirculation of liquid from the outlet 'or discharge line of thepump back to the suction side of thesuch a character as to exercise a compensating function allowingrecirculation of water' as required for priming and also automatically restricting or entirely cutting off the discharge connection against the return or recirculation of water after the pump has been fully primed.-

It is further sought to provide a substantially valveless construction-by so constructing the improved priming feature as to automatically break any siphon action which would otherwise suck away all the priming liquid; another object of this feature of the invention being to render the pump more efllcient by preventing leaks on the intake side of the pump from affecting the pumping means.

Still another object of the invention is to provide a construction in which the improved priming device will not only accomplish the priming function in a more efflcient manner, but may also be adapted to increase the pumps capacity by virtue of the injector actionserving to pump liquid in addition to thatpassingthrough the pumping device proper,

With the foregoing general objects in view, the invention will now be described by reference to the accompanying drawing illustrating one practical form of embodiment of the proposed improvements, after which those features and combinations deemed to be novel will be particularly set forth and claimed. In the drawing- 5 Figure 1 is a vertical sectional view illustrating a self-priming pump constructed in accordance with the present invention, said view representing a section taken on the line ll of Fi ure Figure 2 is a similar view representing a section taken on the line.22 of Figure 1; and

Figure 3 is a sectional detail view showing a modified form of the nozzle or injector device.

Referring now to the drawing in detail, this 15 illustrates the improved apparatus as comprising a supporting structure Ill provided with suitable bearings l2 for the journalling of a shaft H, to which power may be transmitted in any desired manner, as by means of a pulley l5. The stand- 20 ard I0 is formed with a supporting flange l6 to which is secured, as by means of screws H, the outer edge of a casing l8 which is formed with a central packing structure 20 for the shaft l4, and also with a flange 2| for attachment, as by 25 screws 22, to the pump casing 24, al as illustrated in Figure 1. 'The casing 24' is constructed to provide an outer chamber 25 and also an interior volute shell or housing 26 forming an impeller chamber 21 enclosing an impeller member 30 29 of conventional form having the vanes or blades 30, and secured to the end of the shaft ll.

The chamber 25 is provided with the main suction intake connection 32, and the housing 26 is formed with an extension 33 providing an intake 5 passage 34 from the bottom portion of the chamber 25 and discharging centrally through an opening 35 into the impeller chamber 21. Preferably both of said chambers 25 and 21 are provided with suitable drain outlet plugs 36 and 31, 40 respectively.

The housing 26 is formed with a discharge extension 38 fitted with a upwardly projecting and expansible tubular member 40 of rubber or other appropriate flexible or resilient material 45 cured within an opening 44 provided in the bottom of a housing 45 which provides an upper discharge chamber 46 having a discharge outlet l8 and a flller 'plug 49 for the supply of priming fluid to the apparatus whenever necessary. The interior of the tube section 42 is somewhat larger than the diameter of the discharge extension 38 carrying the tubular member 40, as clearly shown in Figure 2. The upper end of said member 40 is normally contracted to leave an annular space 50 between it and the lower end portion of the tube 42 for recirculation of the priming liquid, whereas operation of the pump in the priming action causes the member 40 to expand more or less in accordance with the needs of the priming action, either to simply restrict the return flow of liquid through the space 50 as the priming action progresses, or to completely. shut ofi all such return flow or recirculation after the pump has been completely primed, as indicated by the dotted lines in Figure 2.

In the operation of priming, there is of course a supply of liquid in the chamber 25, preferably on a level approximately with the pump intake 32, and the lower end of the intake passage 34 is located adjacent to the bottom to enable the impeller to utilize practically the full capacity of the chamber however the chamber 25 itself could be made sumciently shallow to make the extension 33 unnecessary. The operation of the impeller in pumping the liquid out of the cham-.

ber 25 into upper chamber 46 creates an initial vacuum in the lower chamber 25. The degree of vacuum is further enhanced by the injector effect produced by the discharge through the tube 40, which is initially contracted and thereby provides an annular space 50 between it and the tube section 42 through which air is sucked upward into the upper chamber. The tube being of nozzle shape during this priming operation, this obviously promotes the aforesaid injector action, while the annular space 50 serves also as a return passage for recirculation of the liquid from the upper chamber into the lower chamber for use in priming. The priming'action takes place in a somewhat intermittent fashion, 1. e., the impeller becomes air-bound intermittently, followed by the pumping of air through the nozzle tube 40, in which operation the air undergoes a compressing action and is discharged with air injector eiTect and further suction of air from the chamber 25 out through the passage 50.

This phase of the priming action might be described as analogous to that produced'by a succession of slugs of the liquid which trap the air between the slugs and carry it on through the impeller until the air is finally released in the discharge chamber and allowed to escape by Way of the outlet 48. So long as the proper deree of vacuum or suction is not reached inthe intake 32, to support the normal pumping operation (as represented by the pump's capacity), the flexible element 40 will not be s'ufi'iciently contracted to close the bypass passage 50, thus permitting enough water to recirculate to the pump for priming purposes. The greater the degree of vacuum or suction which is produced, however, the greater will be the degree of contracting actionimparted to said flexible element, whereby the latter automatically responds to the priming action for restricting the return flow or recirculation of liquid through the space 50, so that only enough recirculation takes place to meet the needs of the priming operation. This recirculation of the priming liquid continues until the air pressure is sufliciently reduced in the lower chamber 25 to effect complete priming of the pump, with a full flow of liquid taking place through the intake to the impeller chamber. When this happens, a full flow of liquid as represented by the pumps capacity is discharged through the outlet 38, whereby the upper portion of the tube 40 is expanded into engagement with the inside of the tube 42 as represented in Figure 1, and by the dotted lines in Figure 2, thus closing the passage and shutting off any return flow of liquid into the lower chamber.

In Figure 3 is illustrated a modification ofthe nozzle or injector device, in which a nozzle ele ment 40 of rigid or suitable metallic material (i: e., without the contracting or expanding properties of the element 40) is employed, and is mounted for sliding movement upon the discharge extension 38 of the chamber 21. This sliding movement may take place within limits permitted by the key 53 and keyway 54 provided between said parts 38 and 40; and, if desired, the length of said keyway may be such as to prevent the entire closing of the byfiow space or passage 50 after the pump is fully primed, in which case the injector action will be continued to produce a supplemental flow or discharge of liquid into the discharge chamber 46 for increasing the pumping capacity beyond that of the impeller chamber itself, as will be readily understood. Obviously the action of the sliding nozzle 40' will be in all respects similar to that of the flexible element 40. as regards producing the injector action already described, and also automatically regulating the size of the return flow passage 50 to meet the needs of the priming function from the initial priming stage up to the time when the pump becomes fully primed.

In some cases, as where the pump is to be operated against a relatively low discharge head and hence with small back pressure, it may be advantageous to key said element 40 for operation as a rigid, fixed injector nozzle, leaving a suitable byflow space 50, but omitting the sliding and automatic regulating function, and still securing the benefit of the increased pumping capacity above referred to.

It will therefore be seen that I have devised a practical and efficient as well as simple and inexpensive self-priming construction, and that the same is of such a type as to require none of the valves ordinarily needed in self-priming devices. That is to say, the impeller chamber and space for the priming supply of liquid are below both the intake 32 and the nozzle structure regulating the discharge to the chamber 46, so that an air space is left between said nozzle structure and the intake; or in other words, the intake and outlet sides of the impeller are left with a means of direct communication, for siphon-breaking purposes, independent of the passage through the impeller chamber, thereby preventing the sucking away of the priming liquid which would otherwise take place. Consequently this eliminates the necessity of valves or the provision of any other mechanical or structural features for such purpose, such as the use of large suction traps to prevent the loss of the priming charge. Moreover this feature has the advantage of preventing the .eiiiciency of the pump being materially decreased by the presence of leaks in the connections on the intake side of the pump.

In either type of nozzle or injector element, the flexible type 40, or the rigid type 40', said element performs the double function of a nozzle for carrying out the injector action, and also by expanding and contracting (or sliding movement in the case of the element 40') a regulating function for restricting or varying the extent of the return flow or recirculation of the liquid back through the bypass 50. As already indicated,

such return flow may be entirely shut ofi when the pump is fully primed, by adapting said adjustable element to entirely close said passage; or if preferred, and particularly in the case of the element 40, some space may be left for further injector action, even after the pump is primed, for producing a further or supplemental flow of liquid in excess of the full normal capacity of the pump as represented by the capacity of the impeller chamber alone. a

It may also be pointed out that the flexible and expansible properties of the tube 40 results in some relative slipping engagement between it and the mouth of the tube- 42, which tends to preventany sticking tendency, which efiect'may be somewhat increased by slightly flaring the lower lip of the tube 42 as shown. While I have indicated rubber as a suitable material for the composition of the tube 40, any flexible material having equivalent expanding and collapsing properties may be employed for the purpose, and

other modifications or changes in the construction may readily be made within the spirit and scope 01' the invention.

I therefore desire to be understood as reserving the right to make whatever changes may properly fall within the scope of the appended claim.

What I claim, and desire to secure by Letters Patent, is:

Self-priming pump apparatus comprising, a structure providing an intake chamber and a discharge chamber connected by a communicating passage, pumping means in said intake chamber, and a tubular expansible element forming a part of the discharge conduit from the pump ing means to said communicating passage, a part of said element being normally contracted into nozzle form projecting into said communicating passage and expanding automatically under internal pressure of the full discharge flow from the pumping means for cutting ofireturn flow of the priming liquid after the pumping means is completely primed, the mouth of said communicating passage being slightly curved for facilitating disengagement of the expansible element on contraction of the latter to normal condition.

RICHARD G. BARZEN. 

